Internal-combustion engine



May 4, 1926. l 1,583,6714 1 G. K.r DAvol.

May 4 4 1,583,671 G. K. DAvol.

INTERNAL COMBUSTION ENGINE Filed August 26, 1921, v s sheets-sheetl 2 Z6 FIG. 2.

/Z Gea/ige E mza 3y 4 E f M waff/zeg? May 4,1926. 1,583-,671 G. K. DAvol.

lNTERNAL COMBUSTION ENGINE Filed August 26, 1921 .3 Sheets-Sheet 3 FIL-14 Patented May 4, 1926.

UNITED STATES sAN EEANCISCdcALIEORNIA, AssIGNoE 'ro CHARLES A.. ..13E0WN, or HrNsnALE, 1LLINoIs.

GEORGE x. Davor., or'

PATENT? OFFICE.

INTERNAL-COMBUSTION ENGINE.

' Application nieu Augst 2e, 1921. semi No. 495,475.

To all 'whom it may concern.' l

Beit known that I, GEORGE K. D'AvoL, a citizen of the United States, residing at San Francisco,'-'i1 i the county of San Francisco and State of California', have invented la certain new anduseful Improvement in Internal-Combustlon Engines, of Vwhich the following is a full, clear, concise, and exact description, reference being had to the accompanyingA drawings, forming a -part of this specication.

My invention relates to internal combustion engines, and mpre'specically to a device for regulating the supply of fuel land air' to an internal combustion engine, or for regulating the ratio between the weight of the air supplied and the weightl of the fuel supplied to such an engine. The invention has particular application to engines in the operation of which the supply of air is restricted atpartial loads, by throttling or otherwise.

In such engines it is desirable to provide for a certain definite variable ratio of weight vof air to weight of fuel in the mixture or charge compressed within the cylinder, to v Y suit various loads and conditions of operation. Thus, for light or partial loads, when the supply of air is restricted or throttled,

the' supply of fuel must also be restricted or cut down, but not ordinarily to the same extent. It is usually found advantageous in the operation of such engines at partial load, when the air supply is throttled or restricted, to supply a richer mixture, or a reduced ratio `of air to'fuel, thanwhen operating at full load with an unrestricted supply of air.v The most advantageous ratio of air to fuel cannot be lfixed, even for any given restriction of air supply, or given density of airdrawn into the cylinder, but for most desirable results'this ratio should be varied to lalso suit the characterv of fuel used, the relative temporary importance of r maximum power output and maximum economy of fuel, andto suit starting conditions and other considerations'.

In the accompanyingdrawings;

Figure 1 is a sectional view taken through the center of one form ofthe device;

Figure 2 is a section on line 2 2 of'Figurel; Y

Figure 3 is al diagram giving curves of, ratios of air Ato fuel. for various degrees of density of air taken into the cylinder of an engine, which curves can be followed in the operation lof the apparatus; and

Figure 4 illustrates a type of engine in connection with which my invention may be used to special advantage.

In 4the form of apparatus I have here shown as embodying myinvention, the supply of air tojthe engine is regulatedby any of4 the customary devices` such' 'as the usual hand operated throttle.

A .connection is made betwee'n the intake pipe or manifold of the engine and the apparatus, whereby the pressure within the intake is arranged to operate on a piston forming part of the devlce. The movement of this piston in one direction is counteracted by a spring, `so that for any given 4vacuum y .within the. intake of the engine a certain definite quantity of fuel must -be sup lied per engine cycle, for any settingl or a Justment of the apparatus, according to some determined law or rule of variation, which in the present state of the art may be most easily determined empirically and expressed graphically by a curve.

.(12) Thisv determinate rule according to which the proportion of fuel to air is governed, (either varied or maintained constant), with varying degrees of density of the air drawn into the engine cylinder, must also be'capable of variation, yto suit variations in character of fuel, and starting and other conditions. y

The essence of my invention lies in that variation of engine intake pressures is translated into movements, which act on the fuel f 25 tain fuels.

65 forming initself a" dash pot or cy ner to fulfill the vabove mentioned requirei ments. With the fuel supplying means of such complete apparatus my invention 1s i less essentially'A concerned, and it is only required that any form of workable device or pump be supplied capable fof having its Iquantity of delivery varied, in some pref-, erably positive manner, as for example 1.0 through the variation of the stroke of the engine orv any-shaft suitably geared to the plunger of a pump.

Referring'to the laccompanying drawings,

. and first to Figure 3, I here -show a diagram giving four curves, -each curve representing `.l a certain vrule of variation. of the ratio of.

fair to fuel with varyingI degrees of intake pressure.A I 'n this diagram theratios of air to fuel are shown to increase with the vertical height above the base while the intake 20 ,pressures are set 0H". horizontally. The curve v `marked A shows the manner-in which the g ratio of airto fuel may be desired t vary with various air densities within the engine 'intakep for: economical operation with cer-- The curve .marked B gives a larger proportion of fuel to thecharge ,for

" all air densities. The curve C gives a stili greater proportion ,of fueleto air or a richer 'mixture for all 'air 'densities 'and may be 39 adapted forl conditions atA starting the engine or for a maximum'. output of power with certain '.fuel, andvcurv'e 'D 4gives still' furtherA enrichment of fuel to the mixture. `These four curves, which may be taken as 435 typical examples of conditions of mixture 1 which maybe desirable under certainl condit-ions of operation, can allbe followed, -as well as other curves which may be plotted between the curves' drawn, Vby the .form `of apparatus I have herein described. 1 i Referring toFigure 1,'the'piston 1, op erating in lthe cylinder 2 formed in the body of the-.apparatus lis bored out and in turn. forms a' cylinder in which is fitted an oil 5 'piston or dash pot'piston 3. -This dash'pot,`

piston 3 is held stationary by. a rod 4f which is secured to the` cover-f 5j fastened to the'- body. An oil Cretaining cover 6'is. suitably 4 secured to the open top of -the' piston 1I 0 and acts to prevent splashing of the 'oil.'

`Itialso forms a seat for the spring 7, thel other end of which bears. against the cover t5. The space shwn above thepiston 1 con-y taining the spring is\fan air tight space enl.,jtirely closed exceptfor the pipe connection or passage 8 through which connection' is made to thev intake pipe or manifold of theI engine. l

It will be seen'that any degree of suction the engine intake will cause a fall of` pressure above the piston 1 and, the lower face of the pistoni being open to the atmosphere, the piston will tend-to rise against the down ward pressure of the spring 7. The piston, 1, linder, `is

I lustdescribed.

supplied with a suitable quantity of oil 9.\- The dash pot piston 3 hasv a hole 10 formed in it, and being held stationary, any movement of the piston 1 will cause the oil to flow through this hole 10I and the movementof the piston 1 will be damped or checked by forcing the oil back and forth through this hole, to prevent too rapid movement of the piston 1. A

The shaft 11 may be `the cam shaft of the 7`5 engine to make one revolution for each complete engine cycle. The cam 12 is formedon the shaft and the Lrevolutions of thislcam cause the. finger 13 to oscillate. This finger is connected by the rod 14 to one end of the lever 15 which lever is guided and held in line by the slotted guide 1G.

The opposite end of the lever 15 is pinned to theupper end of the fuel pump vplunger'35 17 which reciprocates in the cylinder 18. Against the lower end of the plunger the spring 19 bears and tends to force the plunger up. The closed chamber 'beneath the plunger conncctsvby the passage-20 with the intake lvalve 21 and the delivery valve 22 which are here indicated 4as ordinary b all -valves The suction pipe 23 and the delivery vp1pe'2f1f afford connection with y their respecn tive valves. Y

In Figure 2 the ends of three plungers are shown, the apparatus inthe form illustrated beingintended for a three cylinder engine,- and having a separate `pump cylindei for 4each engine cylinder. Each pump plunger having the connecting and operating parts' Above the lever 15 are the vfulcrum rollers 25 which are'mounted on the shaft 2x6. This shaft is held down bythe bearing roll -ers 27, one at veach end of the shaft, which rollers bear against'the holding downplate 28secured to the b ody-vvof-'the" apparatus.

It willrbe seen that revolutions of the cam. 12 acting through the finger .13, ro-d- 14 and lever -15 will causelreciprocating movements of the plunger F17,.the lever 15 bearing against thepfulc-rum roller 25.' The spring 19 acting on the plunger will 'also through these connections keep -linger 13 in contact with camu 12. The extent -of the movements of the f pump plunger 17 will' be regulated by the position of the. fulcrum roller 25, and if this fulcrum roller be moved to a position'direct' ly over the plunger1'7,`the plunger will have. M0 no movement at all imparted vto it. It is thus',possible to communicate to the pump 4plunger all degrees of movement from nothnect in turn with the piston 9. The position i of the piston 9 therefore governs the vertical position of the guide roller 31.

'lhe guide roller 31 moves in a specially formed slot formed in the part 33. This part 33 is pivoted on the pin 34 at its upper end, and its angular position about this pin as center is adjustable through the pinion 35 acting on the toothed segment at its lower end. This part 33 as a whole I term an adjustable profile as this term is most com.- prehensively descriptive of it in any of the many forms ,in whichit can be made. The function of the adjustable profile 33 is to properly translate or transform the movements of the piston 9 (which` are vdirectly proportional to variations in the density of the air drawn into the engine cylinders), to movements which properly vary the delivery of fuel-by the pump plunger or other fuel supplying device.

In making thls translation or modification of movement, compensation must be proper'- ly made for; first, the manner in which the pump delivery is varied, in this case by the shifting of a fulcrum, and second, for the desired variation -'(if any) in the `ratio of air' to fuel.

This translation of movement therefore, involving as it does the following of a curve of a varying 'ratio of air to fuel, as well as sometimes (as in the form of apparatus illustrated), having to compensate for a var ing degree of movement necessary for any given progressive variation in pump delivery, becomes an involved matter. These requirements are rendered still vmore difficult through the necessity -of vproviding for a possible variation of the curve of ratios of air to fuel which must be followed.

To accurately and properly fill these requirements an apparatus capable of eXtreme freedom in its compensating capacity is demanded, and I have been able `to discover orv devise no form of mechanical device that has this unusual' flexibility for compensation to the extent that is supplied by an adjust-,-

able'- profile or guide or a formed profile of adjustable position. Along such 4a profile or guide a roller or follower may be moved proportional to variations in the density of the air supplied to the engine cylinders, and movements resulting from the form of the vprofile be utilized to correspondingly vary the amount of fuel supplied. Such is exactlyv the action of the apparatus herein described.

The movements of the piston 9 proportional to the variations inthe density of the air supplied to the engine cylinders are communicated to the roller 31. This roller moves along 'the adjustable profile formed by the curved slot in the part 33 and the resulting movements of the roller laterally are communicated through the links 29 totheful- If wenow readjust the position'of the.-

adjustable profile 33 by turning the pinion 35 slightly, so that the lower end of the adjustable profile 33 is moved a small distance j to the left, the'- pump will deliver more fuel for any degree of air density, and the resulting ratios ofl air to fuel will be thoseindicated by the curve B in Figure 3. In the same way by readjusting the position of the proile 33 still more to the leftfthe curves Cfand I) can bev followed in the resulting ratios of air to fuel, or any one of an indelinite number of curves of general similarity t can be followed by proper adjustment of the i position of the adjustable profile. 33.

. By modifying the form or curvature `of the slot in the part 33 which forms the pro'- le, curves o`f air-fuel ratios of different form. and characteristics will be followed by theapparatus, and by modifying theposition of the pin 34 on which the adjustable profile is pivoted, achange will -be introduced in the relative characteristics -of the curves@ followed with different settings or adjustments of the profile.

j The fuel may be delivered, for instance, to the supply tube'36 of the engine illus'Y trated in Figure 4. In this engine the main lpiston 38 reciprocating vin cylinder 40 `in casting 4,2, is provided with vanindividual charge compressing piston 44 sliding in cylinder 46.` The charge compressed by piston 44 is liberated towardthe end of the compression stroke by contact block 48 held in place by'set screw. 50 and pressed. upward by springg52. -This block liftsvalve. 54 by movin plunger 56, and permits the compresse charge to pass through portv 58, passage 60, a'check valve designated as an entirety by the reference 62, and passage 64, to bedischarged intocylinder 4() under the control of needle valve 66,

l 68 through head 7 0 held in place by Aclamp 72 and' packing retainer 74, so that thel charge of fuel will be deposited through orifice 76 to be picked up inder 40. p

The cylinder head casting 78 houses inlet valve 80 and a check valve 82 opening into cylinder 44, both valves controlling the flow from a common intake passage 84,'by passages indicated at 86 and 88, respectively.

Supply tube 36 communicates with nozzlel The pressure of the' air supply ,to both valves' may thus be controlled by a single throttle.

Check valve 82 rests on a seat'90 held against shoulder-91-by areetaini'ng nut .92 provided and carried into the cyl' 'with packing 93. Inlet valve `80 is normally held closedby a. spring 94 and opened by i 4rocket 95 pivoted on shaft, 96 and actuated affecting the action of the apparatus or the moved bythe pistonwhich is acted on by essentials ofA the invention. 'l'he adjustable profile 335 is notnecessarily pivoted and adjusted` angularly, but other provision 'may be made for holding'it and adjusting its position. It will'als'o be realized that the adjustable profile may be ithel part that lis,

t le intake pressure,and .the roller or pivot which bears against it may be held relatlvely stationary in line with the movement Lof,` the profile. In ,such an arrangement. special means must be provided for holding rne 'ro--- tile in its various adjustable positions w ile permittingthe movements imparted to -it by the iston.. y l

A'not er' obvious modification would be yto pivot the adjustable proiile and allow an' oscillating movement-to bel imparted to it by the piston about its pivot and provide for adjusting the position of the pivot. Such modilications are obvious and mtro-y duce no change 'in the essentials off themvention. v

'Iclaimz- .p 41.111 combination, an element responsive .to pressures, a fuelv supplying device, means for controlling the deliver of the said fuel supplying device, means, or establishing a connection between the said element' and the controlling means and means for varying '1 the 1 said connection in` accordance with. a

j predetermined ratio.

2. In combination, a fuelv supplying dev vicemeans for actuating said fuel supply- ,3.- In'combination', an element responsive ing'l device, an lelement responsive Ito pressure, means controlled' by the said element for establishing a connection between the said' element. a-nd the -said fuelksupplyinc device, and means for varying the sai connection in accordance with a predetermined ratio;' l

to pressures, a fuel supplying device, 'means' for controlling the deliveryo'f the said fuel supplying dev1ce,.a fulcrum, a second means associated with ythe fulcrum for.varying a the ldelivery'of the fuel supplying device and means for establishing a connection between the fulcrum and thetelementLto control the said `second means. 4. vIn combination a piston responsive tov pressures, a.fuel, supplying device, a memberassociated with the ,'saidgpiston provid- I ed with a slot'andA means connected lto the fuel'supplying deviceand governed by the slot intheniember Vfor controlling the de-l v livery of the fuel supplying device.

5. 'In a fuel regulatorfor internal com-f of said relative movement to said-means for varying the delivery of said pump.

f6. In a vfuel regulator for internal combustion envines, ed on by ti'e pressures Within the intake of tliel engine, a fuelgpump, means for varya fuel pump, means for va-ryof the fuel pump, a proproiile,y connection with proile andlsaid follower, and

a connection for transmitting componentsl j a spring loaded piston actsus ing' .the delivery of said fuel pump, an ad-\` justablel profile, a followerfi'n contact` with said profile, connectionsI translating the movements of said piston into relative movements between said. followerl and said profile, and. connections transmitting components of said relative movements to said means for varying the delivery of said pump. l y f y 7. In a fuel regulator forv internal lcombustion engines, 1a piston acted on -by the pressure Ywithin the intake of the engine, a fuel pump, means. for varying lthe delivery ofthe fuel pump', a profile, `a' follower in contact with-saidprofile, connections transforming movements of said piston intov relative movements between said` profile and said follower, and connections transmitting movements. resultant upon said relative movement between said profile and said follower to saidl means delivery of said pump.

8.In a fuel regulator for internalcombustion engines,'a spring loaded piston actedon by the pressure within the engine in for varying theioo take, a. fuel pump, meansfor varying thel ed 'about a .xed point vand adjustable antact withl said profile and connected with delivery of the fuelpump,- a profile pivot-` said: piston, and connections between 'said follower and (the means for varying the delivery of said pump.

4.9.' In 'a fuel regulator for linternal vcombustion engines, a spring loaded piston actedkon by the pressure within'the engine inta e,J

a fuel pump, means for varying 'the delivery of' said pump, -a profile 'of ad-l justable position, said profile having a l curved slot, a follower movable in said slot, connections Abetween said profile and said piston, and connections between said'followerand said lmeans for varyingthe delivery of said pump. p

'10. `In a fuel regulator for'internal combustion engines, an intake connection, a fuel supplying device, controlling Iheans for governing the delivery of the said fuel supplying means, a piston-responsive to theressure inthe said intake connection, a rst element adapted to reciprocate with the said piston, a pivoted element provided with a slot, a roller riding in the said slot and adapted to be reciprocatedb the said rst element and means for'establishing a l0 connection between the roller and the controlling means.

In witness whereof, I hereunto subscribe my name this 23rd day of August, 1921.

GEORGE K. DAvoL, 

